<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>js</title>

    <script src="http://code.jquery.com/jquery-latest.js" type="text/javascript"></script>
    <script src="../default/js/jquery-2.14.js" type="text/javascript"></script>
    <script type="text/javascript">
        $(document).ready(function () {
            $(window).scroll(function () {
                var a = document.getElementById("eq").offsetTop;
                if (a >= $(window).scrollTop() && a < ($(window).scrollTop() + $(window).height())) {
                    console.log("div在可视范围");
                }else {
                    console.log("不在");
                }
            });
        });
    </script>
</head>
<body>
<div style="width:1px;height:2000px;"></div>
<div id="eq" style=" width:100px; height:100px; background-color:Red;">1</div>
<div style="width:1px;height:2000px;"></div>
</body>
</html>